AFTER THE ATTACKS: THE CANYONS

AFTER THE ATTACKS: THE CANYONS; First Inspections Show Most Buildings Are Structurally Sound

By KIRK JOHNSON and ERIC LIPTON

Published: September 14, 2001

Correction Appended

Shortly before 2 p.m. yesterday, a deep rumble was heard within the American Express building near the remains of the World Trade Center. People yelled and scrambled into the street. Radio reports predicted the imminent collapse of the skyscraper's roof. In the end it turned out to be a piece of masonry falling from a nearby building's facade.

But the questions raised by that brief moment of panic go on and on: What is structurally sound and what is not? How far and how deep does the collateral damage from the staggering impact of two jetliners hitting the Trade Center's two towers, the collapse of those buildings, and the resulting ash, smoke and fire that billowed through the financial district, go?

Building inspectors and engineering consultants who have begun a building-by-building inspection through the area said yesterday that the results so far have been encouraging. Although they found widespread damage that could keep some buildings unoccupied for months, none of the buildings looked at so far, they said, including 14 city-owned buildings, were in danger of falling down or so badly damaged that they could not be repaired. Many of the buildings they inspected will need extensive cleanup or repairs to exteriors and heating and ventilation systems fouled with ash and soot, the inspectors said.

''There has been too much speculation by people not directly involved, predictions of buildings falling,'' said Richard Tomasetti, president of LZA/Thornton-Tomasetti Group, an engineering firm the city has hired to inspect buildings around the World Trade Center. ''In fact, there is no evidence to support all the various speculation, such as rumors that 1 Liberty Plaza or the American Express tower could come down, which is definitely not true.''

Still, the uncertainty lingers. Many building owners have not yet been given permission to re-enter their buildings to conduct their own inspections. Rumors flare about the condition of a particular building, only to dissipate later.

Late Wednesday, New York City Transit halted service on the number 4 and 5 lines in Lower Manhattan -- at the request of the city's Office of Emergency Management -- because of concerns about building structural integrity and the vibrations caused by the trains, said Albert O'Leary, a New York City Transit spokesman.

In a part of New York where much of the land near the Hudson and East Rivers was created with landfill over the last three centuries, and where the ground below the streets and buildings is a latticework of train tunnels, telecommunications cables, and sewer and power lines -- the city simply does not know yet whether it is safe to allow anything like a normal return to the tumult of trucks and trains that was commonplace before.

Mayor Rudolph W. Giuliani said at a news briefing yesterday morning that buildings would be tested ''to determine whether or not they could withstand whatever vibrations the subways would create,'' and that he hoped most subway service could be restored by today.

Above ground, some property owners said they simply did not know the conditions of their buildings. Many are anxious to inspect their properties for themselves, but have been given no word when that might be possible.

''I've heard there was a fire in our building, but I'm not sure, and I heard about the building next door being condemned and I'm not sure whether that's true, either,'' said Mark Aloia, a lawyer for the owner of a 23-story office building at 90 West Street. ''What we're focused on now is getting access with our own structural engineers,'' he said.

Some other building owners who have made their own inspections said yesterday that so far, most of the rumors and speculation about buildings have been wrong.

Brookfield Properties, which owns four large office buildings near the trade center, said in a statement that a ''preliminary technical investigation by independent structural engineers'' had concluded that none of the company's buildings -- 1 Liberty Plaza and towers 1, 2, and 4 of the World Financial Center -- the complex where the American Express building is -- had sustained structural damage.

''Although each of the buildings will require work such as window and lobby repairs, none of the damage renders the buildings inoperable,'' the company said.

An engineer hired by the city, who inspected those buildings yesterday, said that some reports about damage -- notably the possible imminent collapse of 1 Liberty Plaza -- were apparently based on an ''optical illusion.'' On the exterior of the building, the engineer said, there is an area that looks like it is buckling, suggesting possible structural problems.

''If you move over to really look down the edge, where the bulge should be most pronounced, it disappears,'' said David B. Peraza, a vice president at the city's engineering firm, LZA/Thornton-Tomasetti Group, and leader of the company's team of 34 inspectors. ''We got into the building to look for any signs of bulging or separation from the floors,'' Mr. Peraza said. ''We found none.''

Other inspections were less complete. At the Millenium Hilton Hotel, at Church and Fulton Streets, for example, engineers were not allowed to enter the building, so they had to assess it from the outside. From that perspective, no structural damage was observed, Mr. Peraza said.

A building at 30 West Broadway owned by the City University of New York, was just nearing the completion of a $50 million renovation. A spokesman for the university, Michael Arena, said the top floor and facade of the building were damaged by falling debris, and that officials were awaiting permission to return to see for themselves what might be done. The 17-story building was given to the school as a donation in the mid 1990's .

''Now here we are with a big question mark whether this building will be available to us at all,'' Mr. Arena said.

Chart: ''Day Three: Assessing the Scene'' Establishing control over the chaos in Lower Manhattan continued yesterday as inspectors examined the structural integrity of buildings, volunteers continued to dig through rubble, and medical, food and supply units established more permanent positions. The latest assessment and recovery operations: Chart Some Buildings Damaged Some Buildings Collapsed or Partially Collapsed Some Buildings with Major Damage Assessed by Inspectors for Structural Damage 1. 1 World Trade Center (North Tower) 2. 2 World Trade Center (South Tower) 3. Marriott Hotel 4. 4 World Trade Center 5. 5 World Trade Center 6. 6 World Trade Center 7. 7 World Trade Center 8. North Bridge 9. 1 Liberty Plaza 10. East River Savings Bank 11. Millennium Hilton Assessments by building inspectors (As of noon yesterday): Facade, window or no apparent damage 12. Federal Bldg. 13. N.Y. Telephone Building 14. Three World Financial Center Assessments by building inspectors (As of noon yesterday): Appearance or confirmation of structural damage 15. Two World Financial Center Assessments by building inspectors (As of noon yesterday): Facade, window or no apparent damage 16. South Bridge 17. One World Financial Center Assessments by building inspectors (As of noon yesterday): Facade, window or no apparent damage 18. St. Nicholas Greek Orthodox Church 19. 90 West Street Assessments by building inspectors (As of noon yesterday): Appearance or confirmation of structural damage 20. Bankers Trust Assessments by building inspectors (As of noon yesterday): Appearance or confirmation of structural damage 21. Four World Financial Center Assessments by building inspectors (As of noon yesterday): Facade, window or no apparent damage 22. 30 West Broadway Assessments by building inspectors (As of noon yesterday): Appearance or confirmation of structural damage 23. 14 Wall Street Assessments by building inspectors (As of noon yesterday): Appearance or confirmation of structural damage 24. Winter Garden Assessments by building inspectors (As of noon yesterday): Appearance or confirmation of structural damage Map shows location of damaged buildings and relief and counseling areas. Chart: ''Assessing a Building's Fitness'' To determine if a building is safe, engineers inspect its structure and surface. Here are some of the things they examine: PROJECTILE DAMAGE Enormous pieces of debris fell as the towers collapsed. Inspectors look to see if the exterior was punctured or if essential support columns were damaged. BASEMENT WALLS Intense vibrations from the towers' fall may have caused soil consolidation and settling. Engineers look for cracks or chunks falling out, indicating a shift. FROM AFAR Inspectors check for obvious leaning, shifting or cracking that might indicate imminent collapse. They can enter the building if it looks sound. SUPPORTING COLUMNS The most important elements are the columns that hold the building up. Inspectors look for any leaning or cracking. Columns in elevator shafts can sometimes be seen without obstruction. EACH FLOOR Any cracking or depression of the floors might indicate problems with beams or joints between beams and columns. SUBWAY TUNNELS Subway walls support the load of earth above. Inspectors enter the tunnels to look for damage after a visual inspection from entrances. A BUILDING'S SKIN Loose pieces of a glass facade can fall or be blown off. Inspectors look for any misalignment of these exterior elements. (Sources: Thornton-Tomasetti; Jerry Connor, M.I.T.; Skilling Ward Magnusson Barkshire)

Correction: September 16, 2001, Sunday A map and chart on Friday cataloging damage to buildings in Lower Manhattan misstated the condition of 14 Wall Street. It is not on city inspectors' list of buildings with confirmed structural damage, and the owner expects to reopen it on Monday.